1. Field of the Invention
The present invention relates to a core member, a core assembly, a charging port and an induction-type charging apparatus.
2. Description of the Related Art
A typical example of induction-type charging apparatuses employed to charge the batteries in electric cars is disclosed in Japanese Unexamined Patent Publication No. 1995-220961. In the induction-type charging apparatus disclosed in this prior art, a charging coupling device is inserted in a charging port to cause inductive coupling between the charging port and the charging coupling device so that electrical energy to be utilized for charging is supplied from the charging coupling device to the charging port. The charging port includes a secondary core and a secondary winding, whereas the charging coupling device includes a primary core and a primary winding. A gap at which the charging coupling device is to be inserted is provided in advance at the secondary core of the charging port, and by inserting the charging coupling device in this gap, inductive coupling is induced between the charging port and the charging coupling device.
The charging port assumes a structure achieved by inserting the secondary core having the secondary winding inside a case. The secondary core is constituted of an EE core. The EE core achieves a roughly rectangular planar shape.
As mentioned above, the primary application of this type of induction-type charging apparatus is in battery charging in electric cars and in such an application, the charging port is securely mounted near a car battery where other parts also being mounted in close proximity and space is limited. For this reason, it is crucial to miniaturize the charging port as much as possible.
However, since the secondary core constituted of the EE core having a roughly rectangular planar shape and wound with the secondary winding is inserted inside the case of the charging port in the prior art, the EE core can be only pushed in the case as far as the position at which an external circumferential surface of the secondary winding comes in contact with the inner wall surface of the case. This results in a large dead space formed at the far end inside the case and in particular, at the corners of the far end and, thus, the need for miniaturization cannot be satisfied.
It is an object of the present invention to provide a core member and a core assembly that make it possible to realize a charging port and a induction-type charging apparatus which are compact and lightweight.
It is a further object of the present invention to provide a charging port and a induction-type charging apparatus which are compact and lightweight.
In order to achieve the objects described above, the core member according to the present invention comprises a bottom plate portion, a middle leg portion and two outer leg portions. The bottom plate portion has a first direction Y and a second direction perpendicular to the first direction Y. The bottom plate portion has a first side end and a second side end opposing each other in the first direction Y and a third side end and a fourth side end opposing each other in the second direction. The first side end includes inclined side ends which recede from the first side end toward a point which is between the first side end and the second side end and halfway between the third side end and the fourth side end.
The middle leg portion extends from a top surface of the bottom plate portion in a third direction perpendicular to the first direction Y and the second direction, and is offset toward the second side end relative to the center of the bottom plate portion.
The two outer leg portions extend from the top surface of the bottom plate portion in the third direction, along the third side end and the fourth side end, and have top surfaces that are higher than the top surface of the middle leg portion.
The core member described above is used to constitute a charging port in an induction-type charging apparatus. More specifically, two core members are combined together to constitute a core assembly, and the core assembly with a winding wound around the middle leg portion of the core assembly is inserted into the case.
In this structure, at least one of the two core members constituting the core assembly is the core member according to the present invention. In the core member according to the present invention, a gap which allows a charging coupling device to be inserted therein is formed between the middle leg portion and the other core member since the top surfaces of the outer leg portions are set higher than the top surface of the middle leg portion. As a result, the charging coupling device can be inserted into this gap. Since the winding is wound around the middle leg portion of the core assembly, inductive coupling can be induced between the winding wound around the middle leg portion of the core assembly and a winding provided at the charging coupling device via the core assembly, to inductively couple the charging coupling device with the charging port.
In addition, in the core member according to the present invention, the first side end includes inclined side ends which recede from the first side end toward a point which is between the first side end and the second side end and halfway between the third side end and a fourth side end, and the middle leg portion is offset toward the second side end relative to the center of the bottom plate portion. Consequently, the first side end of the bottom plate portion facing opposite the second side end is made to recede relative to the position of the middle leg portion at which the winding is provided. Thus, the core members are housed inside the case by effectively utilizing the space available within the case and achieve miniaturization of the overall case.
Furthermore, since the outer leg portions are provided independently of each along the third side end and the fourth side end of the bottom plate portion, radiation of heat is promoted by utilizing the space between them. As a result, the core volume can be reduced which achieves further miniaturization and a reduction in weight.
At the bottom plate portion, the second side end may be a straight side end. By adopting this mode, the cross sectional area of the bottom plate portion extending from the middle leg portion to the two outer leg portions is increased, making it possible to prevent magnetic saturation which achieves further miniaturization.